Foundry parting



Patented Aug. 11, 1942 UNITED STATES PATENT OFFICE FOUNDRY PAR'IING Marion W. Pitner,- Chicago, 111., assignor, by mesne assignments, to Delta Oil Products Company, a corporation of Wisconsin No Drawing. Application August 2, 1940,

Serial No. 350,082

2' Claims. (01. 22-189) My invention relates to improvements in foundry partings and the process of manufacturing such partings.

It is the primary object of the invention to provide a noveLand commercially satisfactory foundry parting material and process of manufacture thereof, 1

More specifically, it is the object of the present invention first, to avoid the production of a 300 mesh would, in its untreated state, be ideally' suited to foundry parting purposes but for the fact that it is wettable. Previous attempts to make nutshell fiour unwettable have not been waxes or-fats would impregnate the material and make it spontaneously combustible and malodorous in storage. By confining my process to the use Of chemicals I avoid these objectionable commercially successful due in part to spontane-' ous combustion and in part to objectionable odors resulting from the use of soaps and waxes, and

' due in part to the absorption of chemicals by the flour with a consequent abnormally high consumption of the chemicals used for water repellency and alsoto undesirable resistance of the resulting product to passage through th dusting bag used in the foundry. i

Specifically, it is my purpose to avoid the above mentioned difficulties.

My process may be carried out in any container wherein the contents may be heated and mixed. The following is an example of the proportions which may be used in the practice of my process.

To 35 gallons of cold water I add 100 pounds or walnut shell flour, 8.5 pounds of aluminum 'sulphataand 3 pounds of sodium aluminate.

After these materials have been mixed I add an additional 30 gallons of cold water and then raise the entire mixture to the boiling point and boil for five minutes. The product of this treatment is filtered and washed with three successive charges of 30 gallons each of boiling water, after which the product is dried in a vacuum drier.

It will be noted that the amount of chemicals used is relatively small; The weight of chemicals is only slightly greater than the amount of wax which might be used in a process employing waxes or fats as a waterproofing agent. Yet the results. Moreover, by mixing the aluminum sulphate and the sodium aluminate in the presence of the particles of flour, I form directly in the presence of the flour the aluminum oxide which is believed to be adsorbed superficially on the fiour particles and to be responsible for their water repellent characteristics. The formation of alumimun oxide directly in the presence of the fiour and with only a limited period of boiling, precludes absorption or impregnation of the I chemicals into the particles of flour and thereby not only reduces the amount of chemicals which would otherwise be required, but alsomakes a product which is better-suited for use in the dusting bag ofthe foundry.

As a by-product of the production of aluminum hydroxide, which later breaks down into aluminum oxide above referred to, sodium sulphate is produced. This is washed from the product in the final stages of the treatment above described.

I have encountered certain walnut shell fiour which would not satisfactorily respond to the of aluminum sulphate are mixed with gallons foregoing treatment and required the addition of stearic acid. I have, however, discovered how stearic acid may be used in connection with the foregoing process and the foregoing chemicals in a manner which avoids impregnation or absorption of the particles of flour and also avoids the production of a product which would be either spontaneously combustible or ma'lodorous. If it is necessary to'use stearic acid, I practice my process' as follows.

100 pounds of walnut shell flour and 85 pounds ried on as in my first process to wash away the sulphate by-product. The resulting product, even though neo-fat or stearic acid is included, is water repellent by reason of a coating adsorbed upon the particles, rather than impregnated therein, and the particles have the sam distinctive individuality and lack of mutual adhesion cult to examine them adequately, but chemical.

and physical analysis both indicate that th desirable attributes or the product of this invention are attributable to the fact that the anhydrous aluminum oxide which provides the water .repellent characteristic (and the stearic acid,

it small amounts thereof are used in accordance with the second process herein disclosed) are adsorbed superficially upon the particles instead of being absorbed or impregnated therein.

I claim:

1. The treatment of walnut shell flour to produce a foundry parting compound therefrom, which treatment includes the separate preparation of batches of water in one of which there is aluminum sulphate and in the other or which there is sodium aluminate, the introduction or a neo-i'at into one or said batches, the admixture of said batchesln the presence or the flour requiring treatment whereby to deposit upon the particles of flour individual coatings containing aluminum oxide and neo-fat, and the washing and drying of the coated flour.

2. A process of treating walnut shell flour to render it suitable for use as a foundry parting compound, which process includes the mixing of the flour with water and aluminum sulphate in one container. themixing of sodium hydroxide and stearic acid with water in another container, and the saponiflcation or the materials in said second container, the admixture of sodium aluminatewith the saponiiied material in the second container, and the subsequent admixture of 20 the contents oi. the two containers,

MARION W. PITNER. 

